package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSON;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.Shop;
import com.hmdp.mapper.ShopMapper;
import com.hmdp.service.IShopService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.CacheClient;
import com.hmdp.utils.RedisData;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;

import java.time.LocalDateTime;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import static com.hmdp.utils.RedisConstants.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopServiceImpl extends ServiceImpl<ShopMapper, Shop> implements IShopService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    
    @Resource
    private CacheClient cacheClient;

    @Override
    public Result queryById(long id) {
        Shop shop = cacheClient.queryWithLogicalExpire(CACHE_SHOP_KEY, id, Shop.class, this::getById, CACHE_SHOP_TTL, TimeUnit.MINUTES);

        if (shop == null) {
            return Result.fail("店铺不存在！");
        }
        
        return Result.ok(shop);
    }
    
    // private static final ExecutorService CACHE_REBUILD_EXECUTOR= Executors.newFixedThreadPool(10);
    //
    // public Shop queryWithLogicalExpire(Long id){
    //     String key=CACHE_SHOP_KEY+id;
    //
    //     String shopJson = stringRedisTemplate.opsForValue().get(key);
    //    
    //     // 如果缓存不存在
    //     if(StrUtil.isBlank(shopJson)){
    //         return null;
    //     }
    //
    //     RedisData redisData = JSONUtil.toBean(shopJson, RedisData.class);
    //    
    //     Shop shop=JSONUtil.toBean((JSONObject) redisData.getData(),Shop.class);
    //
    //     LocalDateTime expireTime = redisData.getExpireTime();
    //    
    //     // 没有过期
    //     if(expireTime.isAfter(LocalDateTime.now())){
    //         return shop;
    //     }
    //    
    //     String lockKey=LOCK_SHOP_KEY+id;
    //     boolean isLock=getLock(lockKey);
    //    
    //     if(isLock){
    //         CACHE_REBUILD_EXECUTOR.submit(()->{
    //             try {
    //                 this.saveShopToRedis(id,20L);
    //             } catch (Exception e) {
    //                 throw new RuntimeException(e);
    //             }finally {
    //                 unlock(lockKey);
    //             }
    //         });
    //     }
    //
    //     if(StrUtil.isBlank(shopJson)){
    //         return null;
    //     }
    //    
    //     // 没有过期
    //     if(expireTime.isAfter(LocalDateTime.now())){
    //         return shop;
    //     }
    //    
    //     return shop;
    //
    //
    // }
    //
    // public void saveShopToRedis(Long id,Long expiredTime) throws InterruptedException {
    //     Shop shop=getById(id);
    //     Thread.sleep(200);
    //     RedisData redisData = new RedisData();
    //     redisData.setData(shop);
    //     redisData.setExpireTime(LocalDateTime.now().plusSeconds(expiredTime));
    //    
    //     stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY+id,JSONUtil.toJsonStr(redisData));
    // }
    //
    // private Shop queryWithMutex(Long id){
    //     String key=CACHE_SHOP_KEY+id;
    //
    //     String shopJson = stringRedisTemplate.opsForValue().get(key);
    //    
    //     if(StrUtil.isNotBlank(shopJson)){
    //         return JSONUtil.toBean(shopJson, Shop.class);
    //     }
    //    
    //     if(shopJson!=null){
    //         return null;
    //     }
    //    
    //     String lockKey=LOCK_SHOP_KEY+id;
    //     Shop shop= null;
    //    
    //     try {
    //         boolean isLock=getLock(lockKey);
    //
    //         if(!isLock){
    //             Thread.sleep(50);
    //             return queryWithMutex(id);
    //         }
    //
    //         shopJson = stringRedisTemplate.opsForValue().get(key);
    //
    //         if(StrUtil.isNotBlank(shopJson)){
    //             return JSONUtil.toBean(shopJson, Shop.class);
    //         }
    //
    //         shop = getById(id);
    //         if(shop==null){
    //             stringRedisTemplate.opsForValue().set(key,"",CACHE_NULL_TTL,TimeUnit.MINUTES);
    //             return null;
    //         }
    //
    //         stringRedisTemplate.opsForValue().set(key,JSONUtil.toJsonStr(shop),CACHE_SHOP_TTL,TimeUnit.MINUTES);
    //     } catch (InterruptedException e) {
    //         throw new RuntimeException(e);
    //     }finally {
    //         unlock(lockKey);
    //     }
    //
    //    
    //     return shop;
    // }
    //
    // private boolean getLock(String key){
    //     Boolean flag=stringRedisTemplate.opsForValue().setIfAbsent(key, "1",10, TimeUnit.SECONDS);
    //     return BooleanUtil.isTrue(flag);
    // }
    //
    // private void unlock(String key){
    //     stringRedisTemplate.delete(key);
    // }
    //
    // // 缓存穿透
    // private Shop queryWithPassThrough(Long id){
    //     String key=CACHE_SHOP_KEY+id;
    //
    //     String shopJson=stringRedisTemplate.opsForValue().get(key);
    //
    //     if(StrUtil.isNotBlank(shopJson)){
    //         Shop shop= JSONUtil.toBean(shopJson,Shop.class);
    //         return shop;
    //     }
    //
    //     if(shopJson!=null){
    //         return null;
    //     }
    //
    //     Shop shop=getById(id);
    //
    //     if(shop==null){
    //         stringRedisTemplate.opsForValue().set(key,"",CACHE_NULL_TTL, TimeUnit.MINUTES);
    //         return null;
    //     }
    //
    //     stringRedisTemplate.opsForValue().set(key,JSONUtil.toJsonStr(shop),CACHE_SHOP_TTL, TimeUnit.MINUTES);
    //
    //     return shop;
    // }

    @Override
    @Transactional
    public Result update(Shop shop) {
        Long id=shop.getId();
        
        if(id==null){
            return Result.fail("店铺id不能为空");
        }
        
        updateById(shop);
        
        stringRedisTemplate.delete(CACHE_SHOP_KEY+id);
        
        return Result.ok();
    }
}
